[U-Boot] [PATCH v4 09/11] S3C24XX: Add NAND Flash driver

José Miguel Gonçalves jose.goncalves at inov.pt
Wed Sep 19 13:25:25 CEST 2012


NAND Flash driver with HW ECC for the S3C24XX SoCs.
Currently it only supports SLC NAND chips.

Signed-off-by: José Miguel Gonçalves <jose.goncalves at inov.pt>
---
Changes for v2:
   - Coding style cleanup
   - Use of clrsetbits_le32()
   - Use of register bit macros instead of magic numbers

Changes for v3:
   - Removed magic numbers
   - Removed a macro to declare a void printf()
   - Replaced one printf() with a puts()

Changes for v4:
   - Coding style cleanup
   - Use of a struct to store chip private data
   - Replaced u_long by u32
   - Replaced u_char by uint8_t
   - Added error message in s3c_nand_select_chip()
   - Optimization of s3c_nand_hwcontrol()
---
 drivers/mtd/nand/Makefile       |    1 +
 drivers/mtd/nand/s3c24xx_nand.c |  255 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 256 insertions(+)
 create mode 100644 drivers/mtd/nand/s3c24xx_nand.c

diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index 29dc20e..791ec44 100644
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -60,6 +60,7 @@ COBJS-$(CONFIG_NAND_MXS) += mxs_nand.o
 COBJS-$(CONFIG_NAND_NDFC) += ndfc.o
 COBJS-$(CONFIG_NAND_NOMADIK) += nomadik.o
 COBJS-$(CONFIG_NAND_S3C2410) += s3c2410_nand.o
+COBJS-$(CONFIG_NAND_S3C24XX) += s3c24xx_nand.o
 COBJS-$(CONFIG_NAND_S3C64XX) += s3c64xx.o
 COBJS-$(CONFIG_NAND_SPEAR) += spr_nand.o
 COBJS-$(CONFIG_NAND_OMAP_GPMC) += omap_gpmc.o
diff --git a/drivers/mtd/nand/s3c24xx_nand.c b/drivers/mtd/nand/s3c24xx_nand.c
new file mode 100644
index 0000000..384ffbf
--- /dev/null
+++ b/drivers/mtd/nand/s3c24xx_nand.c
@@ -0,0 +1,255 @@
+/*
+ * (C) Copyright 2012 INOV - INESC Inovacao
+ * Jose Goncalves <jose.goncalves at inov.pt>
+ *
+ * Based on drivers/mtd/nand/s3c64xx.c and U-Boot 1.3.4 from Samsung.
+ * Supports only SLC NAND Flash chips.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <nand.h>
+#include <asm/io.h>
+#include <asm/errno.h>
+#include <asm/arch/s3c24xx_cpu.h>
+
+#define TACLS_VAL	7	/* CLE & ALE duration setting (0~7) */
+#define TWRPH0_VAL	7	/* TWRPH0 duration setting (0~7) */
+#define TWRPH1_VAL	7	/* TWRPH1 duration setting (0~7) */
+
+#define MAX_CHIPS	2
+
+/* Struct to store NAND chip private data */
+struct s3c_chip_info {
+	int cs;
+};
+
+static void s3c_nand_select_chip(struct mtd_info *mtd, int chip)
+{
+	struct s3c24xx_nand *const nand = s3c24xx_get_base_nand();
+	u32 nfcont;
+
+	nfcont = readl(&nand->nfcont);
+
+	switch (chip) {
+	case -1:
+		nfcont |= NFCONT_NCE1 | NFCONT_NCE0;
+		break;
+	case 0:
+		nfcont &= ~NFCONT_NCE0;
+		break;
+	case 1:
+		nfcont &= ~NFCONT_NCE1;
+		break;
+	default:
+		printf("S3C24XX NAND: Invalid chip select (%d).\n", chip);
+		return;
+	}
+
+	writel(nfcont, &nand->nfcont);
+}
+
+/*
+ * Hardware specific access to control-lines function
+ */
+static void s3c_nand_hwcontrol(struct mtd_info *mtd, int cmd, unsigned int ctrl)
+{
+	struct s3c24xx_nand *const nand = s3c24xx_get_base_nand();
+	struct nand_chip *this;
+	const struct s3c_chip_info *info;
+
+	if (ctrl & NAND_CTRL_CHANGE) {
+		if (ctrl & NAND_NCE) {
+			this = mtd->priv;
+			info = this->priv;
+			s3c_nand_select_chip(mtd, info->cs);
+		} else {
+			s3c_nand_select_chip(mtd, -1);
+		}
+	}
+
+	if (cmd == NAND_CMD_NONE)
+		return;
+
+	if (ctrl & NAND_CLE)
+		writeb(cmd, &nand->nfcmmd);
+	else
+		writeb(cmd, &nand->nfaddr);
+}
+
+/*
+ * Function for checking device ready pin
+ */
+static int s3c_nand_device_ready(struct mtd_info *mtdinfo)
+{
+	struct s3c24xx_nand *const nand = s3c24xx_get_base_nand();
+
+	return readl(&nand->nfstat) & NFSTAT_RNB;
+}
+
+#ifdef CONFIG_S3C24XX_NAND_HWECC
+/*
+ * This function is called before encoding ECC codes to ready ECC engine.
+ */
+static void s3c_nand_enable_hwecc(struct mtd_info *mtd, int mode)
+{
+	struct s3c24xx_nand *const nand = s3c24xx_get_base_nand();
+
+	/* Set 1-bit ECC */
+	clrsetbits_le32(&nand->nfconf, NFCONF_ECCTYPE_MASK,
+			NFCONF_ECCTYPE_1BIT);
+
+	/* Initialize & unlock ECC */
+	clrsetbits_le32(&nand->nfcont, NFCONT_MECCLOCK, NFCONT_INITMECC);
+}
+
+/*
+ * This function is called immediately after encoding ECC codes.
+ * This function returns encoded ECC codes.
+ */
+static int s3c_nand_calculate_ecc(struct mtd_info *mtd, const uint8_t *dat,
+				  uint8_t *ecc_code)
+{
+	struct s3c24xx_nand *const nand = s3c24xx_get_base_nand();
+	u32 nfmecc0;
+
+	/* Lock ECC */
+	setbits_le32(&nand->nfcont, NFCONT_MECCLOCK);
+
+	/* Return 1-bit ECC */
+	nfmecc0 = readl(&nand->nfmecc[0]);
+
+	ecc_code[0] = nfmecc0 & 0xff;
+	ecc_code[1] = (nfmecc0 >> 8) & 0xff;
+	ecc_code[2] = (nfmecc0 >> 16) & 0xff;
+	ecc_code[3] = (nfmecc0 >> 24) & 0xff;
+
+	return 0;
+}
+
+/*
+ * This function determines whether read data is good or not.
+ * On SLC, must write ECC codes to controller before reading status bit.
+ * If status bit is good, return 0.
+ * If a correctable error occured, correct it and return 1.
+ * If an uncorrectable error occured, return -1.
+ */
+static int s3c_nand_correct_data(struct mtd_info *mtd, uint8_t *dat,
+				 uint8_t *read_ecc, uint8_t *calc_ecc)
+{
+	struct s3c24xx_nand *const nand = s3c24xx_get_base_nand();
+	int ret;
+	u32 nfeccerr0, nfmeccdata0, nfmeccdata1, err_byte_addr;
+	uint8_t err_type, repaired;
+
+	/* SLC: Write ECC to compare */
+	nfmeccdata0 = (((u32) read_ecc[1]) << 16) | read_ecc[0];
+	nfmeccdata1 = (((u32) read_ecc[3]) << 16) | read_ecc[2];
+	writel(nfmeccdata0, &nand->nfmeccd[0]);
+	writel(nfmeccdata1, &nand->nfmeccd[1]);
+
+	/* Read ECC status */
+	nfeccerr0 = readl(&nand->nfeccerr[0]);
+	err_type = nfeccerr0 & 0x3;
+
+	switch (err_type) {
+	case 0:		/* No error */
+		ret = 0;
+		break;
+
+	case 1:
+		/*
+		 * 1 bit error (Correctable)
+		 * (nfeccerr0 >> 7) & 0x7ff     :error byte number
+		 * (nfeccerr0 >> 4) & 0x7       :error bit number
+		 */
+		err_byte_addr = (nfeccerr0 >> 7) & 0x7ff;
+		repaired = dat[err_byte_addr] ^ (1 << ((nfeccerr0 >> 4) & 0x7));
+
+		printf("S3C24XX NAND: 1 bit error detected at byte %u. "
+		       "Correcting from 0x%02x to 0x%02x\n",
+		       err_byte_addr, dat[err_byte_addr], repaired);
+
+		dat[err_byte_addr] = repaired;
+
+		ret = 1;
+		break;
+
+	case 2:		/* Multiple error */
+	case 3:		/* ECC area error */
+		puts("S3C24XX NAND: ECC uncorrectable error detected.\n");
+		ret = -1;
+		break;
+	}
+
+	return ret;
+}
+#endif /* CONFIG_S3C24XX_NAND_HWECC */
+
+/*
+ * Board-specific NAND initialization.
+ */
+int board_nand_init(struct nand_chip *nand)
+{
+	static const struct s3c_chip_info chip_info[MAX_CHIPS] = { {0}, {1} };
+	static int chip_n;
+	struct s3c24xx_nand *const nand_reg = s3c24xx_get_base_nand();
+
+	if (chip_n == 0) {
+		/* Extend NAND timings to the maximum */
+		clrsetbits_le32(&nand_reg->nfconf,
+				NFCONF_TACLS_MASK | NFCONF_TWRPH0_MASK |
+				NFCONF_TWRPH1_MASK,
+				NFCONF_TACLS(TACLS_VAL) |
+				NFCONF_TWRPH0(TWRPH0_VAL) |
+				NFCONF_TWRPH1(TWRPH1_VAL));
+
+		/* Disable chip selects and soft lock, enable controller */
+		clrsetbits_le32(&nand_reg->nfcont, NFCONT_WP,
+				NFCONT_NCE1 | NFCONT_NCE0 | NFCONT_ENABLE);
+	} else if (chip_n >= MAX_CHIPS) {
+		return -ENODEV;
+	}
+
+	nand->IO_ADDR_R = &nand_reg->nfdata;
+	nand->IO_ADDR_W = &nand_reg->nfdata;
+	nand->cmd_ctrl = s3c_nand_hwcontrol;
+	nand->dev_ready = s3c_nand_device_ready;
+	nand->select_chip = s3c_nand_select_chip;
+	nand->options = 0;
+#ifdef CONFIG_SPL_BUILD
+	nand->read_buf = nand_read_buf;
+#endif
+
+#ifdef CONFIG_S3C24XX_NAND_HWECC
+	nand->ecc.hwctl = s3c_nand_enable_hwecc;
+	nand->ecc.calculate = s3c_nand_calculate_ecc;
+	nand->ecc.correct = s3c_nand_correct_data;
+	nand->ecc.mode = NAND_ECC_HW_OOB_FIRST;
+	nand->ecc.size = CONFIG_SYS_NAND_ECCSIZE;
+	nand->ecc.bytes = CONFIG_SYS_NAND_ECCBYTES;
+#else
+	nand->ecc.mode = NAND_ECC_SOFT;
+#endif /* ! CONFIG_S3C24XX_NAND_HWECC */
+
+	nand->priv = (void *)&chip_info[chip_n++];
+
+	return 0;
+}
-- 
1.7.9.5



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